Site News  |   Monitor Keywords  |   Monitor Archive  |   Organizer  |   Account Info  |

Plasma processing apparatus and plasma processing method

The present invention relates to a plasma processing apparatus or plasma processing method for applying a processing such as etching to a sample such as semiconductor wafer by taking advantage of plasma. More particularly, it relates to a plasma processing apparatus or plasma processing method for processing a sample while supplying an electric field into a vacuum container.

In accompaniment with the reduction of the pattern sizes of semiconductor devices, in a plasma processing process of a semiconductor fabrication apparatus, the minimum particulate size which becomes target of particulate reduction is also decreased. Simultaneously, it has also become absolutely necessary to reduce the particulate number. In such a plasma processing apparatus, conventionally, when the particulates increase due to an accumulation of deposited substances caused by repetition of the productions, it has been carried out to clean the apparatus by opening the apparatus into the atmosphere.

Also, in such a plasma processing apparatus, a process referred to as “plasma cleaning” is carried out. In this plasma cleaning, the reaction products deposited inside a processing chamber are removed by the plasma processing. As the plasma cleaning, various processes are carried out, such as a case where the plasma cleaning is carried out between lots of a wafer and a case where the plasma cleaning is carried out on each wafer-processing basis.

Meanwhile, there have been known the following methods: A method of suppressing particulate occurrence by controlling the manner of plasma generation as is disclosed in JP-A-2005-116821, a method of removing particulates by loading factors such as electromagnetic waves, sound waves, and mechanical vibration within the plasma as is disclosed in Japanese Patent No. 2741713 (corresponding to U.S. Pat. No. 5,367,139 etc.), and a method of causing microscopic particles to depart from a stage component member by applying a voltage to a wafer on-board stage, and after that, ejecting the microscopic particles through introduction of a gas as is disclosed in JP-A-2005-101539 (corresponding to U.S. Patent Publication No. 2005/082000).

In this way, the processings for implementing the particulate reduction have been carried out from conventionally. In accompaniment with the reduction of pattern size, however, the request for implementing further particulate reduction is becoming increasingly stronger. Accordingly, technologies which are more effective in the particulate reduction than conventionally is required at present. Namely, in these conventional technologies, adequate consideration has been not yet given to a point of reducing particulates resulting from microscopic particles which adhere to a wall surface inside the vacuum container.

The above-described problem is to reduce the particulates which are produced in the plasma processing. In particular, the problem is to reduce the particulates resulting from the microscopic particles which adhere to the wall surface inside the plasma processing apparatus. Taking the pattern size reduction on semiconductor devices into consideration, it is absolutely necessary to reduce the particulates including the ones whose size is smaller than the particulate size which has been regarded as the problem from conventionally. Incidentally, here, what is referred to as “particulates” means microscopic particles which adhere to a wafer. Meanwhile, what is referred to as merely “microscopic particles” means microscopic particles which do not adhere to the wafer.

It is an object of the present invention to provide a plasma processing apparatus or plasma processing method for suppressing particulates from occurring in a sample located inside a vacuum container.

The above-described object can be accomplished by removing microscopic particles which adhere to surfaces of components or a wall component member of a processing chamber. This elimination is implemented by causing the microscopic particles to depart from the surfaces, and transferring the microscopic particles to outside of the processing chamber. Namely, the above-described object can be accomplished as follows: For the departure of the microscopic particles and under a condition that plasma will not be generated, high-frequency electromagnetic waves are applied into the processing chamber from a plasma source in a predetermined time. Moreover, the microscopic particles are vacuum-exhausted through introduction of a gas into the processing chamber.

In more detail, the above-described object can be accomplished by the following plasma processing apparatus: Namely, a plasma processing apparatus having a processing chamber and a sample base, and processing a sample by using plasma generated inside the processing chamber, the processing chamber being located inside a vacuum container, the sample base being located inside the processing chamber, the sample being mounted on the sample base, the plasma processing apparatus including a component member configuring inner-side wall surface of the processing chamber, and having a dielectric portion on the inner-side wall surface, an exhaustion unit for exhausting the inside of the processing chamber, and an electric-field supply unit for supplying an electric field to the component member in a state where the plasma will not be generated inside the processing chamber, wherein magnitude of the electric field supplied from the electric-field supply unit is changed rapidly while exhausting the inside of the processing chamber by the exhaustion unit.

Otherwise, the above-described object can be accomplished by the following plasma processing method: Namely, a plasma processing method for mounting a sample on a sample base inside a processing chamber, and after that, processing the sample by generating plasma inside the processing chamber, the processing chamber being located inside a vacuum container, and being evacuated by an exhaustion unit, the plasma processing method including a step of supplying an electric field to a component member while exhausting the inside of the processing chamber by the exhaustion unit and in a state where the plasma will not be generated inside the processing chamber, the component member configuring inner-side wall surface of the processing chamber, and having a dielectric portion on the inner-side wall surface, magnitude of the electric field having been changed rapidly.

Further, the above-described object can be accomplished as follows: After supplying the electric field in the state where the plasma will not be generated, the processing chamber is exhausted by the exhaustion unit while introducing a gas into the processing chamber. Also, a gas is introduced into the processing chamber while supplying the electric field in the state where the plasma will not be generated.

Still further, the above-described object can be accomplished as follows: While generating a magnetic field inside the processing chamber, the electric field is supplied in the state where the plasma will not be generated.

Still further, the above-described object can be accomplished as follows: The high-frequency electric field is supplied into the processing chamber from the electric-field supply unit in a state where the sample is not mounted on the sample base, the sample being a processing target.

Still further, the above-described object can be accomplished as follows: After halting the supply of the electric field from the electric-field supply unit, the sample is processed by locating the sample inside the processing chamber, and generating the plasma inside the processing chamber, the sample being a processing target.

Otherwise, the above-described object can be accomplished by the following plasma processing apparatus: Namely, a plasma processing apparatus for locating a sample inside a processing chamber in which a vacuum-processed space is formed, and processing the sample by generating plasma inside the processing chamber, the plasma processing apparatus including a control unit for performing supply/halt of high-frequency power into the processing chamber from the high-frequency power source for generating the plasma under a condition that the plasma will not be generated inside the processing chamber.

Further, the above-described object can be accomplished by the following plasma processing apparatus: Namely, a plasma processing apparatus further including a sample base for locating the sample inside the processing chamber, and a counter electrode countered to the sample base, and wherein the high-frequency power source for generating the plasma is connected to the counter electrode, the supply/halt of the high-frequency power into the processing chamber from the high-frequency power source being performed under the condition that the plasma will not be generated inside the processing chamber.

Also, the above-described object can be accomplished by the following plasma processing apparatus: Namely, a plasma processing apparatus for locating a sample inside a processing chamber, and processing the sample by generating plasma inside the processing chamber by using an induction electric field from outside of the processing chamber, the processing chamber being partially composed of a dielectric, and a vacuum-processed space being formed in the inside of the processing chamber, the plasma processing apparatus including a control unit for performing supply/halt of the induction electric field into the processing chamber under a condition that the plasma will not be generated inside the processing chamber.

Otherwise, the above-described object can be accomplished by the following plasma processing method: Namely, a plasma processing method for locating a sample inside a processing chamber in which a vacuum-processed space is formed, and processing the sample by generating plasma inside the processing chamber, the plasma processing method including a step of performing supply/halt of high-frequency power into the processing chamber from a high-frequency power source for generating the plasma for each sample processing under a condition that the plasma will not be generated inside the processing chamber.

Other objects, features and advantages of the invention will become apparent from the following description of the embodiments of the invention taken in conjunction with the accompanying drawings.